Practitioner-patient direct viewing ophthalmological testing apparatus



June 30, 1970 H. SCHWIND 3,517,933

PRACTITIONER-PATIENT DIRECT VIEWING OPHTHALMOLOGICAL TESTING APPARATUSFiled Jan. 26, 1968 1') Sheets-Sheet 1 FIGJ [ll l llmllll llllllllllllllV i HERBERT scuwmo INVENTOR.

BY I {Karl 91TH Attorney June 30, 1970 H SCHWIND 3,517,988

PRACTITIONER-PATIENT DIRECT VIEWING OPHTHALMOLOGICAL TESTING APPARATUSFiled Jan. 26, 1968' 2 SheetsSheet 53 'FIG.3

HERBERT SCHWIND 59 42 0 INVENTOR.

BY 5 R Patented June 30, 1970 3,517,988 PRACTITIONER-PATIENT DIRECTVIEWING OPHTHALMOLOGICAL TESTING APPARATUS Herbert Schwind, 7Schwarzenberstn, 875 Asehalfenburg, Germany Filed Jan. 26, 1968, Ser.No. 700,798 Int. Cl. A61b 3/02 US. Cl. 351-30 4 Claims ABSTRACT OF THEDISCLOSURE A patient, seated in a chair, views a display of projected ortransluminated symbols while the ophthalmologist, seated nearby andfacing the patient, observes the same symbols on a panel directly infront of him; for this purpose the display apparatus is coupled with astepping switch which successively energizes a series of lamps disposedbehind an array of stationary slides lying behind the observation panelor forming part thereof, each slide so illuminated being a substantialreplica of a symbol concurrently displayed to the patient.

My present invention relates to an ophthalmological apparatus and, moreparticularly, to an installation for testing the eysight of a patient bymeans of luminous symbols of different shape and/or size displayed at apredetermined distance from his eyes.

During such examination it is generally necessary that the practitionerstands or sits close to the patient, facing him, in order to fitdifferent lenses to the patients eyes or to observe his reactions. Thisposition makes it inconvenient for the examining doctor to view thedisplayed symbols flashed onto a screen behind his back. A need exists,accordingly, for equipment enabling the practitioner to observe thesesymbols on a separate panel directly in front of him without requiringhim to turn his head away from the patient.

The object of my present invention is to provide an apparatus of thisdescription which effectively reproduces the displayed symbols on suchan observation panel by simple electromechanical means.

This object is realized, pursuant to my present invention, by anophthalmological apparatus wherein a patients seat confronts a screenfor the display of the aforedescribed luminous symbols, theophthalmologist occupying a position facing the patients seat whilemanipulating the display device at a nearby control post; an array ofstationary pictures, eg a set of slides, are displayed at that post andare individually illuminable by associated lamps so synchronized withthe'display device that the appearance of any symbol on the viewingscreen coincides with the illumination of a picture representing asubstantial replica of such symbol.

Although, in principle, the display device may be coupled with the lampselector in a variety of ways, I prefer for this purpose a steppingswitch mechanically synchronized with the dislay means and co-operatingwith a bank of contacts respectively assigned to the individual lampsassociated with these pictures. Such mechanical coupling positivelyco-ordinates the two displays and prevents faulty correlation such ascould occur with, say, a synchronous servo drive. This kind of couplingcan be conveniently used with either a disk-type projector or a A slideselector according to my invention may be readily installed behind anobservation panel at the control post, the panel advantageouslyincluding a groundglass plate which is interposed between the lamps andthe slides mounted thereon. Naturally, these slides and thecorresponding image carriers of the display device may be removable forreplacement or exchange.

The invention will be described in greater detail with reference to theaccompanying drawing in which:

FIG. 1 is a perspective view of an ophthalmologigsts office equippedwith an apparatus according to the invention;

FIG. 2 is a somewhat diagrammatic view of the internal construction ofthe apparatus; and

FIG. 3 is another partly diagrammatic view, illustrating a modification.

In FIG. 1 I have shown a patients chair 10 confronting a viewing screen11 onto which a set of luminous symbols 12 are successively flashed bymeans of a projector 13. This projector stands on a console 14 oppositean ophthalmologists chair 15; a control panel 16 faces the practitionerseated on chair 15 and is flanked by various switches and knobs 17 foractuating the projector 13 and performing other operations associatedtherewith, e.g. the dimming of the room illumination. Console 14 alsosupports a post 18 on which an arm 19 is swingable, this arm carrying apair of frames 20 to be fitted with lenses through which the patient mayview the display 12. A headrest 21 and a lamp 22 are representative ofadditional equipment that may be mounted on or near the chair 10.

FIG. 2 illustrates details of the projector 13 and the control panel 16.The projector includes a disk 23 keyed to a shaft 24 which is driven bya motor 25 through an electromagnetic clutch 26. Shaft 24 also drives,directly or through an interposed gear transmission not shown, a wiperarm 45 of a stepping switch with a multiplicity of bank contacts 46.Each of these contacts is connected via a respective lead 27 to acorresponding lamp 28 disposed in an orthogonal array of light fixturesbehind a groundglass plate 29 which carries a set of slides 30individually aligned with the lamps 28. A glass panel 31 in a frame 32overlies the assembly of slides 30. The lamps 28 are housed inindividual compartments of an opaque supporting structure 33 whichshields adjoining slides from translumination by the energized lamp.

Disk 23 is formed with as many peripheral notches 34 (here 12) as thereare contacts 46 and lamps 28 as well as slides 30, these notches beingengageable by a pawl 35 under tension from a biasing spring 36. Anelectromagnet 37 coacts with pawl 35 when energized from a source ofelectric current, shown as a battery 38, upon closure of a switch 39which may be part of the control equipment on console 14. Retraction ofpawl 35 from its notch 34 releases the disk 23 and, by engaging acontact 40, closes an energizing circuit for motor 25 and magneticclutch 26. Disk 23 and wiper then rotate in unison until the pawl 35drops into the next notch 34 after the release of switch 39; thus, ashort actuation of this switch steps the projector disk from one notchto the next whereas a sustained closure allows it to rotate through alarger angle. In each operating position, in which the detent 35, 36 iseffective, a lamp 41 behind disk 23 transluminates a respective slide 42in one of 12 cutouts of the disk; an objective 44 casts the image ofthat slide onto the screen 11 of FIG. 1.

The slides 30 on panel 16 are respective replicas of the slides 42 ondisk 23 whose position thereon is so correlated with that of wiper 45that the slide transluminated by lamp 41 in any disk position is thecounterpart of the slide transluminated at the same time by a lamp 28energized over the corresponding contact 46. The practitioner seated onthe chair 15 of FIG. 1 thus observes on panel 16 a reduced replica ofthe symbol concurrently flashed onto the screen 11.

FIG. 3 illustrates a different display device which does not require abeam projector and can therefore also be used with ambient illumination.This device comprises a film strip 47 which is unwound from a roll 48and wound upon a roll 49 under the control of a drive motor 50 adaptedto be energized by way of a manual switch 51. The shaft 52 of roll 49carries a bevel gear 53 meshing with a similar gear 54 on a leadscrew 55which mates with a nut 56. A bank of contacts 46a on an upright bar 57are individually engageable by a wiper arm 45a to complete a circuit viaa respective lead 27a to one of the lamps 28 of the panel 16 of FIG. 2.Strip 47 carries a set of transparencies 42a transluminable by abox-shaped light source 58 behind the strip. Another electric motor 59can be operated through a switch 60 to rewind the strip 57 on roll 48.The ophthalmologist observing the patient may, without turning around,control the advance of film strip 47 by opening the switch 51 as soon asthe desired image appears on panel 16 The spacing of bank contacts 46aon bar 57 decreases progressively in the direction of advance of nut 56(here downwardly) to take into account the increasing diameter of theroll 49 with the strip 47 Wound thereon, since, with the images 42aequispaced on the strip, the angle of rotation for shifting from onesymbol 42a to the next is progressively reduced. As long as the end ofstrip 47 is fixedly attached to a predetermined generatrix of roll 49,the switch 45a, 46a again positively correlates the two displays, i.e.the transparencies 42a of FIG. 3 and the illuminated slides 30 of FIG.2.

It will thus be seen that I have provided a system which, in a simpleand efiicient manner, enables an ophthalmologist on his chair 15 to dealwith a patient on seat 10 while simultaneously monitoring the display ofsymbols on screen 11 by observing their (usually reduced) counterpartson panel 16.

I claim:

1. An ophthalmological apparatus comprising a patients seat; displaymeans including a movable image carrier for consecutively exhibiting aseries of luminous symbols at a predetermined location remote from andin front of said patients seat; a control station in the vicinity ofsaid seat including a stationary structure independent of said displaymeans with a set of compartments open toward a common side, a set oflight sources in said compartments, a stationary holder for a set ofslides positioned adjacent said structure for individual transluminationof its slides by said light sources, and a display panel in front ofsaid holder viewable from a position facing said seat, said slides beingsubstantial replicas of the luminous symbols exhibited by said displaymeans; selector means operable from said control station for displacingsaid carrier to different positions exhibiting respective symbols; andswitch means mechanically coupled with said carrier for individuallyenergizing the light source associated with the slide corresponding toan exhibited symbol whereby the replica of such symbol is simultaneouslydisplayed on said panel.

2. An apparatus as defined in claim 1 wherein said image carriercomprises a slide support, said display means including an opticalobjective positioned to project pictures of the slides on said supportonto a viewing screen.

3. An apparatus as defined in claim 1 wherein said image carriercomprises a partly transparent strip, said display means including aslight source positioned behind said strip for transluminating thesymbols thereof.

4. An apparatus as defined in claim 3 wherein said selector meanscomprises a pair of rolls having respective ends of said strip fastenedthereto and drive means for rotating said rolls to unwind said stripfrom one roll and wind it up on the other roll, said switch meansincluding movable contact means coupled with said drive means fordisplacement thereby and stationary contact means positioned forintermittent engagement by said movable contact means.

References Cited UNITED STATES PATENTS 1,558,348 10/1925 Ferree et a1.35130 1,761,239 6/1927 Scott 351-36 X 2,120,596 6/1938 Avey 353-212,137,702 11/1938 Ruby 351-36 2,738,702 3/1956 Angenieux 353-21 FOREIGNPATENTS 478,418 2/1953 Italy.

OTHER REFERENCES Compact Acuity Projector, Bausch & Lomb Optical Co.Reference Manual Cat. No. 71-34-40, pp. 2, 4-10.

Shuron Monitor 505 Projector, Shuron Optical Co. Direction Manual, pp.1, 3, 5, 6, 8, 9, 16 (pp. 1 and 16 are the front and back cover).

DAVID SCHONBERG, Primary Examiner P. A. SACHER, Assistant Examiner U.S.Cl. X.R. 35132, 36

